Children of obese parents feel the consequences into middle-age

Children of obese parents are up to five times more likely to be overweight or obese by the time they reach their forties, new research has found

The study, by the Institute of Child Health (ICH) at University College London, is thought to be the first in the world to track the link between parents’ weight and that of their children into mid-adulthood.

Researchers looked at information from just over 4,000 people participating in the 1970 British Cohort Study to analyse weight patterns over a 32-year span – from age 10 to age 42.

Girls and boys were found to be equally likely to become overweight or obese as children, but two-thirds of men (63%) became overweight or obese in early adulthood (age 26-34), compared to only one-third of women (31%). Only 15 per cent of men were never overweight or obese between 10 and 42 years of age, compared to 40 per cent of women.

Women were therefore much more likely than men to maintain a healthy weight in early adult life, possibly due to uneven societal pressures, although this cannot be assessed from this study.

The study found that the higher the parents’ Body Mass Index (BMI) was, the more children were at risk of being overweight or obese by the time they were 42.

Children with one parent classed as obese – a BMI of 30 or higher – were just over three times more likely to be persistently overweight or obese between age 10 and 42 than those with parents who had a healthy BMI of 22.

Those with two obese parents were up to five times more likely to be persistently overweight or obese from age 10 onwards.

The vast proportion of those who became overweight or obese at any age remained so in their mid-forties.

The study also found that girls were slightly more influenced by their mother’s BMI than boys were. The daughters of obese mothers with a BMI of 30 were at more than triple the risk of being overweight or obese from childhood onwards, compared with girls who had a mother with a BMI of 22.

For boys with obese mothers this risk was doubled. Having a father with a BMI of 30 also doubled the risk of being overweight or obese from childhood onwards for both boys and girls.

The new ICH study highlights the need to prevent obesity early in life, as obesity is associated with type 2 diabetes, coronary heart disease and other causes of death. Since both parents influence obesity in their adult children, researchers recommend early intervention focusing on the whole family, particularly for overweight children with overweight parents.

Dr Silvia Costa, one of the study’s authors, said: “What’s striking is that we found parents’ weight to have such a long-term impact on their children’s weight, long after they have left home. Even in those who were not overweight as children, higher parental BMI significantly increased the risk of being persistently overweight during adulthood, even taking into account other factors known to influence obesity such as coming from a more deprived background or mother’s education.

“Further investigation is needed to unpick whether the influence of parents’ weight on their offspring is down to genetic influences, the home environment, shared habits like unhealthy eating or lack of exercise that their children may pick up and maintain through to adulthood, or a combination of all these factors.

“Our research reinforces the need for early intervention involving the whole family to prevent obesity before it starts, especially as the vast majority of people maintain excessive weight – whether they first become overweight during childhood or later during early adulthood.”

Read the full paper

Additive influences of maternal and paternal body mass index on weight status trajectories from childhood to mid-adulthood in the 1970 British Cohort Study  (2015) by Silvia Costa, William Johnson and Russell M Viner.

The paper is published as part of the Centre for Longitudinal Studies (CLS) Working Papers  series. It will be available from the CLS website www.cls.ioe.ac.uk from 9am today (27 March) but journalists can request an advance copy. The paper will also appear in the Spring issue of the Longitudinal and Life Course Studies journal.

Further information

Katya Nasim
k.nasim@ioe.ac.uk
020 7612 6354

Ryan Bradshaw
r.bradshaw@ioe.ac.uk
020 7612 6516

Notes for editors

1. The study aimed to describe the weight status trajectories from childhood to mid-adulthood and investigate the influence of maternal and paternal body mass index (BMI) on their children’s trajectories, after controlling for other factors. The sample comprised 4,174 participants from the 1970 British Cohort Study with complete BMI data at ages 10, 26, 30, 34 and 42 years.
2. Body Mass Index, or BMI, is a ratio of weight for height, and is used as a measure of how over or underweight someone is. A person of healthy weight has a BMI of 19-25, while someone with a BMI of 25-29.9 is classed as overweight, and those with a BMI of 30 or higher would be classed as obese.
3. Please follow the link for more information about the Institute of Child Health, University College London (UCL).
4. The 1970 British Cohort Study (BCS70) is following the lives of more than 17,000 people born in England, Scotland and Wales in a single week of 1970. Over the course of cohort members’ lives, BCS70 has collected information on health, physical, educational and social development, and economic circumstances, among other factors. Since the birth survey in 1970, there have been eight surveys at ages 5, 10, 16, 26, 30, 34, 38 and 42. The 1970 British Cohort Study is managed by the Centre for Longitudinal Studies at UCL Institute of Education.
5. The Centre for Longitudinal Studies (CLS) is an Economic and Social Research Council resource centre. It is based at the Department for Quantitative Social Science, UCL Institute of Education. CLS is responsible for running four of Britain’s internationally-renowned cohort studies: the 1958 National Child Development Study, the 1970 British Cohort Study, the Millennium Cohort Study and Next Steps (previously known as the Longitudinal Study of Young People in England).
6. The UCL Institute of Education Is a world-leading university specialising in education and the social sciences. Founded in 1902, the Institute currently has more than 7,000 students and 800 staff. In the 2014 QS World University Rankings, the Institute was ranked number one for education worldwide. It has been shortlisted in the ‘University of the Year’ category of the 2014 Times Higher Education (THE) awards. In January 2014, the Institute was recognised by Ofsted for its ‘outstanding’ initial teacher training across primary, secondary and further education. In the most recent Research Assessment Exercise two-thirds of the publications that the IOE submitted were judged to be internationally significant and over a third were judged to be ‘world leading’. www.ioe.ac.uk
7. Founded in 1826, UCL was the first English university established after Oxford and Cambridge, the first to admit students regardless of race, class, religion or gender, and the first to provide systematic teaching of law, architecture and medicine. We are among the world’s top universities, as reflected by performance in a range of international rankings and tables. UCL currently has over 35,000 students from 150 countries and over 11,000 employees. Our annual income is over £1bn.
8. The Economic and Social Research Council (ESRC) is the UK’s largest funder of research on the social and economic questions facing us today. It supports the development and training of the UK’s future social scientists and also funds major studies that provide the infrastructure for research. ESRC-funded research informs policymakers and practitioners and helps make businesses, voluntary bodies and other organisations more effective. The ESRC also works collaboratively with six other UK research councils and Innovate UK to fund cross-disciplinary research and innovation addressing major societal challenges. The ESRC is an independent organisation, established by Royal Charter in 1965, and funded mainly by the Government. In 2015 it celebrates its 50th anniversary. www.esrc.ac.uk